1. Field of the Invention
The present invention relates generally to high temperature polymers, and more specifically to high temperature polymer blends including a phthalonitrile resin.
2. Description of the Background Art
In U.S. Pat. No. 4,619,986, issued Oct. 28, 1986, to Teddy M. Keller, the entirety of which is incorporated herein by reference for all purposes, phthalonitrile resins having the formula: ##STR1## are blended with epoxy monomers having the formula: EQU R--O--A--O--R,
where A is selected from the group consisting of --.phi.--C.sub.n H.sub.2n --.phi.--, --.phi.--SO.sub.2 --.phi.--, --.phi.--, --C.sub.n H.sub.2n -- and --.phi.--.phi.-- wherein n ranges from 1-4, the phenyl groups are linked at the para or meta positions, and R is selected from the group consisting of linear epoxies having 3-5 carbon atoms. When polymerized, the blend forms a polymer of greatly improved thermo-oxidative stability relative to the amine-cured epoxy. However, the thermal stability of the polymerized blend is less than that of the amine-cured phthalonitrile polymer.